• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.127-133
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• 2013

As an essential part of current industrial society, electric power energy is contantaly increasing in pace with the development of science and technology. In order to meet the demand of electric power, power facilities which take care of the higher voltage and bigger capacity is required. To produce and supply electric power on a sound basis the electric facilities should operate with reliability. To prevent disasters in advance, the high quality facilities should be manufactured, and a constant management should be done. When the power facilities cause accidents, the result is huge national deficits. Since the power facilities play a pivotal role in the key industry of national infrastructures of they should operate for a long time in maintaining a stable state, and the accidents can be prevented in advance. The lifetime of a power cable is considered to be 30 years at the time of manufacture, but in real fields, accidents of cable occur 8-12 years from the start of operation, resulting in a heavy loss of properties. In this paper, we will show that we have found out the cause and process of the deterioration of 22kV cable systems in operation. The result is that the process of deterioration does not follow the Weibull distribution only ; but rather, after the heat deterioration the Weibull distributed deterioration comes, then the cable is destroyed due to the partial discharge resulting from the Weibull distributed deterioration.

• Journal of Digital Convergence
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• v.15 no.10
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• pp.437-444
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• 2017

Christopher Nolan's film "Inception (2012)", which depicts the world of dreams as a unique space-time and opens a new chapter in the expression of dreams, portrays the dreamy world of unconsciousness. However, I can find limitations and contradictions in the expression of the actual dreams and essence of unrealistic structures and forms. I can find David Lynch's movies "Mulholland drive (2001)", which are closer to Freud's psychoanalysis in expressing the actual presentation process of dreams Through comparative analysis, I try to analyze the interpretation and context of the dream mentioned by Freud. The film "Inception" can be appreciated in terms of space time and rich imagination created from the point of view of science fiction movies, but it shows that logical reasonability is weak in view of applying the essence of dream. On the other hand, the film "Mulholland Drive" describes the illogical, confusing and unhappy feeling of unconsciousness by giving logic and order based on the interpretation of Freud's psychoanalytic dreams, is. In this way, it is possible to portray more realistic scenes of dreams only through the portrayal of dreams and unconsciousness based on Freud's psychoanalytic viewpoint.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1773-1784
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• 2021

In order to minimize damage to oil spill accidents in the ocean, it is essential to collect a spilled area as soon as possible. Thus satellite-based remote sensing is a powerful source to detect oil spills in the ocean. With the recent rapid increase in the number of available satellites, it has become possible to generate a status report of marine oil spills soon after the accident. In this study, the oil spill area was calculated using various satellite images for the Symphony oil spill accident that occurred off the coast of Qingdao Port, China, on April 27, 2021. In particular, improving the accuracy of oil spill area determination was applied using high-resolution commercial satellite images with a spatial resolution of 2m. Sentinel-1, Sentinel-2, LANDSAT-8, GEO-KOMPSAT-2B (GOCI-II) and Skysat satellite images were collected from April 27 to May 13, but five images were available considering the weather conditions. The spilled oil had spread northeastward, bound for coastal region of China. This trend was confirmed in the Skysat image and also similar to the movement prediction of oil particles from the accident location. From this result, the look-alike patch observed in the north area from the Sentinel-1A (2021.05.01) image was discriminated as a false alarm. Through the survey period, the spilled oil area tends to increase linearly after the accident. This study showed that high-resolution optical satellites can be used to calculate more accurately the distribution area of spilled oil and contribute to establishing efficient response strategies for oil spill accidents.

• Journal of The Korean Association For Science Education
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• v.26 no.4
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• pp.502-509
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• 2006

The purpose of this study was to analyze physics problem solving processes according to students' cognitive style in the area of 'Force and Motion' at high school level. Students who have already learned t e area of 'Force and Motion' during the first semester of the 10th grade have taken physics test and cognitive style test to choose students who have basic knowledge of physics and reflective or impulsive style. Four students who got over 19 points in the cognitive style test were selected as reflective students, and another four students who got below 12 points were selected as impulsive students. After explaining the purpose and procedure of this study, think-aloud method was introduced to the students, and the students practiced it. After that, the students solved three quantitative and qualitative problems each. Then, the questionnaire on the belief system on physics and physics problem solving and prerequisite knowledge test were also administered. By recording the students' problem solving processes, protocol was made and analyzed. After solving the problems, the students expressed their confidence, intimacy, and preference on each problem by the five point Likert scale. Impulsive students tended to succeed in solving more problems, less intimate, and more spontaneous and positive in seeking alternative solution when confronted with unacquainted problems. On the other hand, reflective students used more time in executing the problems even without planning, and used more time in solving problems and verification. Whether making effective plan or not was important rather than how much time they used in the planning step. In addition, repeating steps were more likely shown to impulsive students; they tended to be attached to their first idea.

• Journal of Gifted/Talented Education
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• v.13 no.4
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• pp.65-94
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• 2003

The purpose of this study is to acquire the information on the current situation of students' selection process in order to renovate the system of picking up the students. As a first step of the study, we examined the validity of the factors of the single-out system such as qualification and the process for the application and the standards and proceeding of the selection. Then we analysed the result of the entrance examination of Hansung Science Highschool in 2002. The analysis was on the correlation between the result of entrance examination and the achievement in the school and the decision of the course after graduation. To know on the achievement of the students, we investigated the records of regular tests and asked the teachers' opinion in math and science classes. As a result, we gained the following points: First, the present single-out system has a danger of excluding students who are much talented in science and math field because it is based on students' achievements in middle schools; Second, the new selection system should consider the character and attitude of the applicants in addition to their knowledge; Third, the continuous observation of the teacher in middle school should be an important factor of the picking up system; Fourth, more questions requiring divergent thinking ability and inquiry skill should be developed as selective examination question. Also examination questions should cover the various contents from mathematics to science, and do not affect pre-learning; Finally, the system of present letting all students stand in one line should be changed into that of letting students in various lines. We can consider using multi-step selection system.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.512-518
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• 2022

In this study, safety devices for ammonia tanks of a company in Ulsan petrochemical industrial complex were studied. The type of a tank is cylindrical and this tank was originally designed to store propylene in 1972. Due to the changes of the production schedule according to market environments, the usage of this tank has been changed to store ammonia. Despite of the changes of materials, there is no scientific information or reviews for guaranteeing the safety. Therefore, in this study, the current status of this tank is investigated to confirm that the operational conditions are complying with safety conditions. Moreover, the safety devices such as an ammonia absorbing system and water curtains are analyzed how they mitigate the impact of an accident. In addition, consequence analysis is performed to provide a proper emergency response plan. Throughout these analysis, it is confirmed that installed safety devices effectively mitigate the impact of accidents, and the necessary time for an emergency response plan is suggested when ammonia release.

• 한국정책학회보
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• v.23 no.4
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• pp.179-209
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• 2014

Transition studies have been gaining attention among innovation researchers from the early 1990's mainly influenced by emerging global agendas on sustainability. In this paper, we review research issues and trends focusing on four prominent transition theories - Technological innovation systems, Multi-level perspective, Transition management and Strategic niche management. After reviewing main characteristics, research trends and debates of each theory from established literatures, we conduct comparative analysis of these theories and suggest integrated framework that can be considered when modeling transition policy. This integrated framework is applied to the case study on smart-grid policy of Korea.

• Journal of the Korean Chemical Society
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• v.53 no.6
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• pp.774-783
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• 2009

The purpose of this study was to survey the secondary science teachers' viewpoints of basic particles conceptions addressed in science course. The first content of this study was to analyze the secondary science teachers conceptions related to basic particles founded on scientific history viewpoints. The second content was to investigate their understanding of relations between atom, element, and molecule concepts. The third content was to search the factors influenced on basic particles conceptions of science teachers. For this study, 96 secondary science teachers were selected. The data of this study were collected through a questionnaire developed for this study and were analysed using the method of constant comparative analysis. The results showed that their viewpoints towards basic particles were similar to each other regardless of their majors and their conceptions belonged to the past viewpoints. The teachers lacked linking understand among basic particles conceptions because they applied different viewpoints on different problems. Most of the teachers were influenced on science textbooks, guidebooks for teachers, and reference books to form confusing viewpoints of basic particles.

• Journal of Educational Research in Mathematics
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• v.24 no.2
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• pp.125-143
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• 2014

In this study, we analyzed a mathematical discussion in the Calculus II course of the Gifted Science Academy and individual interviews to determine the relationship between cognitive conflicts and commognitive conflicts. The mathematical discussion began with a question from a student who seemed to have a cognitive conflict about the osculating plane of a space curve. The results indicated that the commognitive conflicts were resolved by ritualizing and using the socially constructed knowledge, but cognitive conflicts were not resolved. Furthermore, we found that the cause of the cognitive conflict resulted from the student's imperfect analogical reasoning and the reflective discourse about it could be a learning opportunity for overcoming the conflict. These findings imply that cognitive conflicts can trigger the appearance of commognitive conflicts, but the elimination of commognitive conflicts does not imply that cognitive conflicts are resolved.

• Child Health Nursing Research
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• v.19 no.4
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• pp.282-290
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• 2013

Purpose: The purpose of this study was to analyze life respect-related content in the 7th to 10th grade textbooks of middle and high schools. Methods: Sixty two textbooks adopted as middle and high school textbooks were analyzed for content on life respect. Results: There were 6 categories related to life respect content in the 7th to 9th grade textbooks ("prevention of accidents and the first-aid", "mental health", "sex and health", "prevention of drug abuse, smoking and drinking", "normal life and health", and "society and health"). Content on life respect in the 10th grade textbooks was categorized as "drug abuse, smoking, drinking, and health", "sex and health", "mental health", "life science and treating human life too lightly", "normal life and health", and "society and health". Conclusion: Content on life respect attached importance to more practical issue such as prevention of violence and suicide rather than fundamental understanding about self and life. These results suggest that the content on life respect should help adolescents find their own values and meaning of life within the concept of coexistence.